Many electronic systems include a printed circuit board with several integrated circuit devices connected to the PCB. Frequently, these integrated circuit devices are connected to the PCB by solder. For example, integrated circuit devices, such as ball grid arrays (BGAs) are utilized in a circuit along with other electronic components that are connected to the PCB by solder. BGAs typically include at least one solder ball arranged between the integrated circuit device and the printed circuit board at each contact so as to electrically connect the integrated circuit device to the circuit board.
The solder balls are attached to an associated plurality of conductive surface pads located on the bottom surface of the ball grid array (BGA) package. The BGA package including the solder balls and the solder paste are placed onto the PCB, wherein the solder balls and solder paste are reflowed to form BGA joints, which in turn attach the BGA package to the PCB.
BGAs have become quite prevalent in the commercial electronics industry, and many useful devices are packaged in this manner. In general, BGA joints do not offer the life and reliability that is required in the commercial electronics industry, due to the fact that, because of their dumpling shape, the BGA joints are not pliant enough to absorb mechanical shock, such as those experienced by an accidental dropping of a cell phone. This can result in solder ball damage on either the bottom surface of the BGA package side or the PCB side, which in-turn can result in disjoining the BGA from the PCB.
One method aims to improve the BGA joint reliability by changing substrate plating to, such as Ni plating, on the bottom surface of the BGA package to strengthen the BGA joint. However, this method does not address the underlying problem of the relatively low height and dumpling shape of BGA joints, which results in a lower shear strength solder joint structure.